Nurul Fadzillah Fadhar, Pravin Kumran Nyanasegran, Mohd Firdaus-Raih, Sheila Nathan, Mohd Anuar Jonet, Chyan Leong Ng
{"title":"Protein expression, purification, crystallization and crystallographic studies of BPSL0741 from Burkholderia pseudomallei","authors":"Nurul Fadzillah Fadhar, Pravin Kumran Nyanasegran, Mohd Firdaus-Raih, Sheila Nathan, Mohd Anuar Jonet, Chyan Leong Ng","doi":"10.1107/S2053230X24008197","DOIUrl":"10.1107/S2053230X24008197","url":null,"abstract":"<p><i>Burkholderia pseudomallei</i> is the causative agent of the lethal disease melioidosis. This bacterium infects animals and humans and is increasingly resistant to multiple antibiotics. Recently, genes associated with survival of the bacterium in the infected host have been identified. One of these genes, <i>bpsl0741</i>, is annotated as a hypothetical protein of 185 amino acids. Here, recombinant BPSL0741 (rBPSL0741) protein was expressed, purified, verified by mass spectrometry, crystallized and analyzed by X-ray diffraction. rBPSL0741 was crystallized by vapor diffusion using a reservoir solution consisting of 0.2 <i>M</i> ammonium acetate, 0.1 <i>M</i> sodium acetate trihydrate pH 4.6, 30% PEG 4000. The crystals diffracted to 2.1 Å resolution using an in-house X-ray diffractometer and belonged to an orthorhombic space group, with unit-cell parameters <i>a</i> = 62.92, <i>b</i> = 64.57, <i>c</i> = 89.16 Å. The Matthews coefficient (<i>V</i><sub>M</sub>) was calculated to be 2.18 Å<sup>3</sup> Da<sup>−1</sup>, suggesting the presence of two molecules per asymmetric unit and an estimated solvent content of 43.5%. The crystal was deemed to be suitable for further structural studies, which are currently ongoing.</p>","PeriodicalId":7029,"journal":{"name":"Acta crystallographica. Section F, Structural biology communications","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graham Chakafana, Reghan Boswell, Andrew Chandler, Krishelle A Jackson, Sanai Neblett, Tyler Postal, Sandhya Subramanian, Jan Abendroth, Peter J Myler, Oluwatoyin A Asojo
{"title":"Structures of Brucella ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein reveal a conformationally flexible peptide-binding cavity.","authors":"Graham Chakafana, Reghan Boswell, Andrew Chandler, Krishelle A Jackson, Sanai Neblett, Tyler Postal, Sandhya Subramanian, Jan Abendroth, Peter J Myler, Oluwatoyin A Asojo","doi":"10.1107/S2053230X24007027","DOIUrl":"10.1107/S2053230X24007027","url":null,"abstract":"<p><p>Brucella ovis is an etiologic agent of ovine epididymitis and brucellosis that causes global devastation in sheep, rams, goats, small ruminants and deer. There are no cost-effective methods for the worldwide eradication of ovine brucellosis. B. ovis and other protein targets from various Brucella species are currently in the pipeline for high-throughput structural analysis at the Seattle Structural Genomics Center for Infectious Disease (SSGCID), with the aim of identifying new therapeutic targets. Furthermore, the wealth of structures generated are effective tools for teaching scientific communication, structural science and biochemistry. One of these structures, B. ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein (BoLBP), is a putative periplasmic amino acid-binding protein. BoLBP shares less than 29% sequence identity with any other structure in the Protein Data Bank. The production, crystallization and high-resolution structures of BoLBP are reported. BoLBP is a prototypical bacterial periplasmic amino acid-binding protein with the characteristic Venus flytrap topology of two globular domains encapsulating a large central cavity containing the peptide-binding region. The central cavity contains small molecules usurped from the crystallization milieu. The reported structures reveal the conformational flexibility of the central cavity in the absence of bound peptides. The structural similarity to other LBPs can be exploited to accelerate drug repurposing.</p>","PeriodicalId":7029,"journal":{"name":"Acta crystallographica. Section F, Structural biology communications","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11376275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tim Garbers, Piotr Neumann, Jan Wollenhaupt, Achim Dickmanns, Manfred S Weiss, Ralf Ficner
{"title":"Crystallographic fragment screen of the c-di-AMP-synthesizing enzyme CdaA from Bacillus subtilis.","authors":"Tim Garbers, Piotr Neumann, Jan Wollenhaupt, Achim Dickmanns, Manfred S Weiss, Ralf Ficner","doi":"10.1107/S2053230X24007039","DOIUrl":"10.1107/S2053230X24007039","url":null,"abstract":"<p><p>Crystallographic fragment screening has become a pivotal technique in structure-based drug design, particularly for bacterial targets with a crucial role in infectious disease mechanisms. The enzyme CdaA, which synthesizes an essential second messenger cyclic di-AMP (c-di-AMP) in many pathogenic bacteria, has emerged as a promising candidate for the development of novel antibiotics. To identify crystals suitable for fragment screening, CdaA enzymes from Streptococcus pneumoniae, Bacillus subtilis and Enterococcus faecium were purified and crystallized. Crystals of B. subtilis CdaA, which diffracted to the highest resolution of 1.1 Å, were used to perform the screening of 96 fragments, yielding data sets with resolutions spanning from 1.08 to 1.87 Å. A total of 24 structural hits across eight different sites were identified. Four fragments bind to regions that are highly conserved among pathogenic bacteria, specifically the active site (three fragments) and the dimerization interface (one fragment). The coordinates of the three active-site fragments were used to perform an in silico drug-repurposing screen using the OpenEye suite and the DrugBank database. This screen identified tenofovir, an approved drug, that is predicted to interact with the ATP-binding region of CdaA. Its inhibitory potential against pathogenic E. faecium CdaA has been confirmed by ITC measurements. These findings not only demonstrate the feasibility of this approach for identifying lead compounds for the design of novel antibacterial agents, but also pave the way for further fragment-based lead-optimization efforts targeting CdaA.</p>","PeriodicalId":7029,"journal":{"name":"Acta crystallographica. Section F, Structural biology communications","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11376277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crystal structure of the Rib domain of the cell-wall-anchored surface protein from Limosilactobacillus reuteri","authors":"Yi Xue, Zhen Wu, Xue Kang","doi":"10.1107/S2053230X24007970","DOIUrl":"10.1107/S2053230X24007970","url":null,"abstract":"<p>The immunoglobulin (Ig)-like domain is found in a broad range of proteins with diverse functional roles. While an essential β-sandwich fold is maintained, considerable structural variations exist and are critical for functional diversity. The Rib-domain family, primarily found as tandem-repeat modules in the surface proteins of Gram-positive bacteria, represents another significant structural variant of the Ig-like fold. However, limited structural and functional exploration of this family has been conducted, which significantly restricts the understanding of its evolution and significance within the Ig superclass. In this work, a high-resolution crystal structure of a Rib domain derived from the probiotic bacterium <i>Limosilactobacillus reuteri</i> is presented. This protein, while sharing significant structural similarity with homologous domains from other bacteria, exhibits a significantly increased thermal resistance. The potential structural features contributing to this stability are discussed. Moreover, the presence of two copper-binding sites, with one positioned on the interface, suggests potential functional roles that warrant further investigation.</p>","PeriodicalId":7029,"journal":{"name":"Acta crystallographica. Section F, Structural biology communications","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142085851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crystal structure of the GDP-bound human M-RAS protein in two crystal forms","authors":"Stephanie M. Bester, Rebecca Abrahamsen, Luiza Rodrigues Samora, Wen-I Wu, Tung-Chung Mou","doi":"10.1107/S2053230X24007969","DOIUrl":"10.1107/S2053230X24007969","url":null,"abstract":"<p>M-RAS plays a crucial role in the RAF–MEK signaling pathway. When activated by GTP, M-RAS forms a complex with SHOC2 and PP1C, initiating downstream RAF–MEK signal transduction. In this study, the crystal structure of the GDP-bound human M-RAS protein is presented with two forms of crystal packing. Both the full-length and truncated human M-RAS structures aligned well with the high-confidence section of the <i>AlphaFold</i>2-predicted structure with low r.m.s.d., except for the Switch regions. Despite high sequence similarity to the available mouse M-RAS structure, the full-length human M-RAS structure exhibits unique crystal packing. This inactive human M-RAS structure could offer novel insights for the design of selective compounds targeting M-RAS.</p>","PeriodicalId":7029,"journal":{"name":"Acta crystallographica. Section F, Structural biology communications","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142085850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}